1. Field of the invention
The present invention relates to a process for the preparation of polystyrene immobilized rhodium catalysts for the hydroformylation of olefins, and more particularly relates to such hydroformylation of olefins in the presence of a sulfonated polystyrene containing rhodium complexes.
2. Description of the Prior Art
Catalysts for the hydroformylation of olefins are well known in the art to produce aldehydes by hydroformylation. The reaction usually carried out by reacting an olefin with carbon monoxide and hydrogen in an organic liquid medium which contains, as catalyst, a compound based on a metal of Group VIII of the periodic classification or table of elements, and especially which contains a soluble complex formed from one of the above metal compounds and at least one organic ligand which has, in its molecule, and atom of an element of Group VA of the periodic classification, such as tertiary arsines, tertiary stibines or tertiary phosphines.
Among the catalyst systems to date envisaged, those complexes resulting from the reaction of an inorganic or organic derivative of rhodium appear the most attractive. However, a notable disadvantage of those liquid phase hydroformylation processes above described require a difficult supplementary treatment for the purpose of separating the hydroformylation products from the catalyst solution. Then, many methods have been developed for attaching transition metal complexes to a polymer support to eliminate the disadvantage of soluble catalysts.
It is well known in the prior art to use crosslinked poly(styrene-divinylbenzene) copolymer as a support for the production of a polymer immobilized catalyst. Polymer immobilized catalysts have advantages of homogeneous catalyst and heterogeneous catalyst.
It has been long recognized that the homogeneous processes suffer from the difficulties of separating the catalyst from the products and it is for this reason that methods for immobilizing transition metal species on the solid supports have been studied in detail.
Polymer immobilized catalyst has an advantage of easy recovery and possible reuse and these advantages offer to reduce the production cost.
It is well known in the prior art to make these catalysts by attaching metal catalyst on the polymer support via covalent bonding or ionic bonding. Especially, in the case of polystyrene immobilized catalyst, the catalyst has been made by attaching a metal catalyst on the crosslinked polystyrene support. This polystyrene support has been functionalized by chloromethylation and phosphination reaction. This method is well knowen prior art.
For example, Pittman et al. [J. Amer. Chem. Soc., vol. 97 (1975), page 1742-1748], hereby incorporated by reference, made a polystyrene support by chloromethylation and phosphination and attached nickel, rhodium or ruthenium complex to this support. However, these catalyst have a less catalytic activity than their homogeneous counterparts in the hydroformylation of 1-pentene.
Batchelder et al. [6th International Congress on Catalysis, (1976) page 499-508], hereby incorporated by reference, made a polystyrene support containing amine functional groups and phosphine functional groups to investigate the catalytic activity in the hydroformylation of propylene at 80.degree. C. and 86 atm. This catalyst had a higher catalytic activity at first, however the activity decreased rapidly with reaction progress.
De Munck et al. [J. Mol. Catal., vol. 10 (1981) page 313-330], hereby incorporated by reference, made a polystyrene support by chloromethylation and chlorophosphonation and attached rhodium complex to this support containing phosphine and phosphite functional groups. However, the activity of this catalyst decreased rapidly with reaction progress in spite of milder reaction condition.
Other many report has been suggested that the metal catalyst immobilized on the polymer support has a lower activity and the activity decreased rapidly with repeated use due to the severe metal leaching.
The activity of conventional polymer immobilized metal catalyst is decreased rapidly with reaction progress and the efficiency of that catalyst has a problem due to the severe metal leaching, then these catalysts cannot be used be used commercially.
Therefore, the object of this invention is the preparation of new polystyrene immobilized rhodium catalyst which has a high activity and stability in the hydroformylation of olefins.
A further object of this invention is the preparation of new polystyrene immobilized rhodium catalyst which has a high activity in the hydroformylation of olefins in aqueous phase reaction.